According to a recent IDC Research report, the U.S. mobile instant messaging (“IM”) market was predicted to reach $365 million in 2004 and is expected to reach $1.2 billion by 2008. However, the current paradigm for IM, adoption of which has been so successful in the desktop PC environment and which cell phone manufacturers have only just begun to offer access to in mobile devices as of the filing date of this patent application, is not easy to use in the mobile environment. In particular, the current IM paradigm is encumbered by the constraint that one can only communicate with those who are currently (i) online, (ii) logged on to same IM service such as AOL's Instant Messenger (AIM), Yahoo! Messenger or MSN Messenger, and (iii) included as a “buddy” on one's “buddy list.”
Patent application Ser. No. 10/817,994, entitled “Peer-to-Peer Instant Messaging Method and Device” (hereinafter, the P2P patent application) provides techniques for a new paradigm for mobile IM that eliminates these limitations and operates in a manner that all are familiar with—the cell phone. For example, in one embodiment of the P2P patent application, by opening a TCP/IP port on one's smart phone and sending the TCP/IP address and port (whether permanent or temporary) to a recipient's phone number through the Short Message Service (SMS), one is able to develop an IM system wherein (i) the initiator dials the cell phone number of the recipient (i.e., sending the SMS message containing the TCP/IP address and port), (ii) the recipient's cell phone rings (i.e., the recipient receives the SMS message), and (iii) if the recipient chooses, he is able answer the call and engage in a real-time text conversation, just like a typical voice call (i.e., the recipient's smart phone extracts the TCP/IP address and port from the SMS message and establishes a direct TCP/IP connection with the initiator). This new yet familiar paradigm essentially turns the restrictive “buddy list” of the current IM paradigm into the entire cellular network.
However, peer-to-peer techniques such as those described in the P2P patent application also have their limitations. Specifically, with pure peer-to-peer IM techniques, it is more difficult to implement a commercially viable IM system that efficiently incorporates the capability to communicate in a real-time messaging session with more than two devices (i.e., adding conferencing capabilities to an IM system). Additionally, to the extent service providers dynamically allocate private IP addresses (rather than allocate public Internet IP addresses) to mobile devices through Network Address Translation (NAT) or any other network address allocation techniques, peer-to-peer IM techniques such as those described in the P2P patent application will only work within the private network of the service provider since the private IP addresses allocated to a mobile device will not be properly resolved by a receiving mobile device residing on a separate private network with a separate service provider. As such, what is needed is a server-based IM architecture based upon the core teachings of the P2P patent application to address the conferencing and private network limitations discussed above.